Conventionally, as imaging apparatuses typified by digital video cameras, there are those that automatically adjust the exposure time of an image sensor or change the method of reading out pixels of the image sensor according to an imaging mode that is set. Specifically, for example, in the case where the imaging mode is set to a night scene mode, the method of reading out pixels is changed to pixel summing (a method of summing pixel values of a plurality of adjacent pixels and reading out the values as the pixel value of one pixel).
Also, there are conventional imaging apparatuses that are provided with a mechanism for detecting camera shake, and there is proposed a control method of adjusting the exposure time of an image sensor or changing the pixel summing method of the image sensor according to the detected amount of camera shake.
For example, Patent Document 1 proposes a control method according to which, when the imaging mode is set to the night scene mode, if the detected amount of camera shake is great, the number of pixels whose pixel values are to be summed in the pixel summing method is set to be great, and if the detected amount of camera shake is small, the number of pixels whose pixel values are to be summed in the pixel summing method is set to 1, for example, so that all pixel readout is performed without performing pixel summing.
According to this control method, even with the night scene mode, if the amount of camera shake is small, a high-resolution image may be obtained. On the other hand, if the mode is the night scene mode, and the amount of camera shake is great, an image for which camera shake has been corrected by pixel summing may be obtained.
However, the amount of camera shake is not necessarily uniform across the entire frame, and in the case where a frame includes an area with a great amount of camera shake and an area with a small amount of camera shake, an image with the highest possible resolution is desirably output by performing pixel summing for the area with a great amount of camera shake and performing all pixel readout for the area with a small amount of camera shake.
Additionally, in relation to control of an image sensor on a per-area basis by dividing the image sensor into a plurality of areas, for example, Patent Document 2 proposes an image sensor which allows the exposure time to be changed on a per-area basis.